openpower/sv/grevlut.py

   1 def lut2(imm, a, b):
   2     idx = b << 1 | a
   3     return (imm>>idx) & 1
   4
   5 def dorow(imm8, step_i, chunk_size):
   6     step_o = 0
   7     for j in range(64):
   8         if (j&chunk_size) == 0:
   9            imm = (imm8 & 0b1111)
  10         else:
  11            imm = (imm8>>4)
  12         a = (step_i>>j)&1
  13         b = (step_i>>(j ^ chunk_size))&1
  14         res = lut2(imm, a, b)
  15         #print(j, bin(imm), a, b, res)
  16         step_o |= (res<<j)
  17     #print ("  ", chunk_size, bin(step_o))
  18     return step_o
  19
  20 def grevlut64(RA, RB, imm, iv):
  21     x = 0
  22     if RA is None: # RA=0
  23         x = 0x5555555555555555
  24     else:
  25         x = RA
  26     if (iv): x = ~x;
  27     shamt = RB & 63;
  28     #print (bin(shamt), bin(63))
  29     for i in range(6):
  30         step = 1<<i
  31         if (shamt & step):
  32             x = dorow(imm, x, step)
  33     return x & ((1<<64)-1)
  34
  35
  36 if __name__ == '__main__':
  37     # answer: 8888888...
  38     RB = 0b0000
  39     imm = 0b11000110
  40     x = grevlut64(None, RB, imm, 1)
  41     print ("grevlut", bin(RB), bin(imm), hex(x), "\n", bin(x))
  42
  43     # answer: 8888888...
  44     RB = 0b0010
  45     imm = 0b11000110
  46     x = grevlut64(None, RB, imm, 1)
  47     print ("grevlut", bin(RB), bin(imm), hex(x), "\n", bin(x))
  48
  49     # answer: 80808080...
  50     RB = 0b00110
  51     imm = 0b11000110
  52     x = grevlut64(None, RB, imm, 1)
  53     print ("grevlut", bin(RB), bin(imm), hex(x), "\n", bin(x))
  54
  55     # answer: 80008000...
  56     RB = 0b01110
  57     imm = 0b11000110
  58     x = grevlut64(None, RB, imm, 1)
  59     print ("grevlut", bin(RB), bin(imm), hex(x), "\n", bin(x))
  60     print()
  61
  62     # answer: 01010101...
  63     RB = 0b00110
  64     imm = 0b01101100
  65     x = grevlut64(None, RB, imm, 0)
  66     print ("grevlut", bin(RB), bin(imm), hex(x), "\n", bin(x))
  67
  68     # answer: 00010001...
  69     RB = 0b01110
  70     imm = 0b01101100
  71     x = grevlut64(None, RB, imm, 0)
  72     print ("grevlut", bin(RB), bin(imm), hex(x), "\n", bin(x))
  73     print()
  74
  75     for RB in range(64):
  76         imm = 0b11000110
  77         x = grevlut64(None, RB, imm, 1)
  78         print ("grevlut", bin(RB), bin(imm), hex(x), "\n", bin(x))
  79     print()
  80
  81     for RB in range(64):
  82         imm = 0b01101100
  83         x = grevlut64(None, RB, imm, 0)
  84         print ("grevlut", bin(RB), bin(imm), hex(x), "\n", bin(x))
  85     print()
  86
  87     for RB in range(64):
  88         imm = 0b10011010
  89         x = grevlut64(None, RB, imm, 1)
  90         print ("grevlut", bin(RB), bin(imm), hex(x), "\n", bin(x))
  91     print()
  92
  93     for RB in range(64):
  94         imm = 0b01011010
  95         x = grevlut64(None, RB, imm, 1)
  96         print ("grevlut", bin(RB), bin(imm), hex(x), "\n", bin(x))
  97     print()
  98